Do you have access to a gym?
Sophia, best of luck in toning your inner thighs!
If it was me, I would do excercizes like squats, which work the big muscles in that area, over several days. You could even hold some weights while performing the squat to make it more difficult. With squats you'll notice your heart rate increase quickly too, they're great for keeping you in shape!
Other than that I would probably suggest cycling, I got into cycling a year ago and now I'm really happy with my legs! Best of luck, there are lots of leg excersises on here.
And remember to rest!